1. Field of the Invention
This invention relates to a novel antitumor or anti-neoplastic agent, composition and treatment. More particularly, it is directed to compositions comprising a stilbene derivative and a platinum coordination compound, such as the drug Cisplatin. Such compositions have been discovered to be safe and highly effective anti-neoplastic agents and are thus useful for the prevention, amelioration, treatment or cure of neoplasms, cancer, and tumors, particularly malignant or solid tumors. These compositions may optionally include other therapeutic compounds or agents. The invention is also directed to methods of using a composition comprising a stilbene derivative and a platinum coordination compound, and to methods of co-administration of these compounds to prevent, ameliorate, treat, or cure neoplasms, cancer or tumors.
2. Discussion of the Background
There is a pronounced need for safe and more efficacious anti-tumor agents. While a wide variety of chemotherapeutic agents are presently used for the treatment, suppression and prevention of tumors, tumors may develop a resistance to such agents, especially highly malignant or solid tumors. Thus, tumor relapse is a common problem. Also, existing agents, even if effective, may be inconvenient to administer in effective dosages and have inadequate therapeutic indexes. Thus, patients may suffer from pain and other side-effects of their administration, especially from the administration of high doses of anti-tumor agents with relatively low potencies.
Platinum coordination compounds, such as Cisplatin and other diamino-platinum complexes, have been widely used in humans as chemotherapeutic drugs. The platinum coordination compound used in the present invention is such a compound which gives platinum preferably in an ionic form, and preferably is a compound exhibiting substantial anti-tumor activity, more preferably a platinum coordination compound exhibiting tumor cell proliferation preventative or inhibiting properties. Many platinum coordination compounds used in the present invention are commercially available or may be manufactured by known or routinely used techniques. However, these compounds are not therapeutically effective for all patients or all types of tumors. For instance, numerous attempts have been made to improve Cisplatin-based therapy by using Cisplatin in combination with other drugs. Although some attempts have achieved improvements in efficacy, these compositions were not sufficiently effective in treating tumors, reducing tumor burden, or in relieving the pain and other complications suffered by tumor patients. Thus, there is a need to discover other agents which together with a platinum coordination compound would be more efficacious in treating tumors.
Cisplatin or cis-diamminedichloroplatinum (II) has been successfully used for long as a chemotherapeutic drug in the therapy of various malignant tumors in the human being.
More recently, other diamino-platinum complexes have shown efficacy as chemotherapeutic drugs in curing various malignant tumors in the human being. Examples of the diamino-platinum complexes may be spiroplatinum and carboplatinum.
Cisplatin and other diamino-platinum complexes have been widely used as chemotherapeutic drugs in the humans. However, these are not therapeutically efficient for all patients or all sorts of tumors. In expectation of possibly increasing therapeutic efficacy, numerous attempts have been made towards using Cisplatin in combination with Vindesine, see Garalla, R. J. et al., Ann. Intern. Med. 95: 414-420 (1980) or using Cisplatin in combination with VP-16, see Congeval, E. et al., Cancer, 51: 2751-2756 (1982). Although such combined application has achieved certain improvement in the efficacy ratio, it cannot be said that the tumor burden or pains of tumor-bearing patients has been completely relieved by these measures.
Stilbene derivatives which have cis-stilbene as a fundamental skeleton, are known to strongly inhibit mitosis and cause cytotoxicity. However, existing stilbene derivatives have not been available or practical as pharmaceutical agents for a number of reasons, including their low solubilities in water.
Recently, certain stilbene derivatives which inhibit tubulin polymerization and having improved solubility in water have been investigated, for instance, the phosphorylated pro-drug Combretastatin-A4, see U.S. Pat. No. 5,561,122. Other stilbene derivatives having improved solubility in water have been proposed as drugs, such as those of the present Assignee as described for instance in Japanese Patent Kokai Publications JP-A-7-228558 and JP-A-8-301831. While such stilbene derivatives are promising, alone they may exert insufficient anti-tumor activity. Thus, it is desired to enhance the antitumor efficacy and safety of compositions containing stilbene derivatives.